Automatic rotating sprinkler head



Aug. 18, 1931. w. VAN E. THOMPSON AUTOMATIC RO'ITINCTv SPRINKLER.4 UJAD 2 Sheets-Sheet l Filed Dec. 8, 1926 .-f--I'Aug. 18, 1931. w. VAN E. THOMPSON AUTOMATIC ROTATING SPRINKLER HEAD 2 sheets-sheet 2 Filed Dec. 8, 1926 f E7/TOR.- WALTfR MQNE. 5?'

Patented Aug. 18, 1931 air Ars WALTER VAN E. THOMPSON, OF LOS ANGELES, CALIFORNIA, ASSIGNOR TO THOMPSON MANUFACTURING COMPANY, OF LOS ANGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA AUTOMATIC ROTATING SPRINKLER HEAD Application filed December 8, 1926.` Serial No. 153,276.

My invention relates to irrigation sprine klers and particularly to a revolving irrigation sprinkler having certain novel features which will be hereinafter described.

Revolving sprinklers are used for watering lawns, playgrounds, golf-courses, and for overhead orchard irrigation, the principal feature being that they are capable of irrigating very large areas. A` common type of revolving sprinkler has a rotatable body from which arms extend. At the outer ends of the arms are tangential nozzles. The water passes through the body and from the tangential nozzles. There is a reaction of the wat-er on the body which causes it to revolve. The streams of water flowing from the nozzles irrigate a circular area around the sprinkler.

In the ordinary sprinkler the head rotates comparatively fast, and this rotation pro-- duces a whipping action which reduces the throw of the water and consequently reduces the area which may be irrigated by the sprinkler.

It is an object of this invention to provide an irrigation sprinkler in which the head will rotate slowly so that there will be no whipping of the streams of water issuing therefrom.

The tvpe of sprinkler in general use today cannot be rotated slowly because the head will freeze: consequently the head must be rotated fast or it will not rotate at all.

A further object of this invention is to provide a revolving sprinkler in which the head cannot freeze.

Another object of this invention is to provide a revolving sprinkler in which the rate of rotation of the head may be varied to suit conditions.

Another object of the invention is to provide a revolving sprinkler in which the wind resistance will not materially affect the rota- 45 tion of th-e head;

In the ordinary sprinkler the water issuing from-the nozzles is .in a state of turbulence. and considerable kinetic energy is thereby dissipated. By removing the tur- 50 bulent action from the water before it issues from the. sprinkler it is possible to obtain a i l. longer throw. f 2 It is accordingly an object of this inven tion to provide a sprinkler in which the turbulence is removed from the water before it issues from the nozzle of the sprinkler.

The ordinary manner of rotatably supportingl the head of the sprinkler is to provide apair of telescopically related tubes, one being attached to the sprinkler head, and the other being stationary and attached to the source of water supply. 'Ihe contacting surfaces of these tubes constitute the bearing surfaces. The nozzle through which the water issues is usually. above the bearing, and this distance is increased. in heads including rotating means or other devices. The reactionary force of the water on the head tends to twist the head to swing the axis of the ybearing tube secured to the head at an 'angle to thev axis of the stationary tube. Due to the distanceV of the nozzle above the bearing, the force tendingto twist the head is increased in proportion to the lever arni or distance of the point of application of the reactionary force from the bearing. Thebearing surfaces arefcaused to be worn at each end due to the twisting of the head, and due tothe surface engagement being relatively small as compared 30 with the entire bearing area intended to take the weight, the wear is comparatively rapid. The bearing soon leaks and if the water carries any abrasive particles, as it usually does, the particles lodgebetween the surfaces and `35 the rate of wear is augmented.y It is an object of niy invention to provide a sprinkler in which the arm carrying the. nozzle and the nozzle are so designed and positioned lthat the' reactionary force of the 90 water issuing froin'the nozzle acts in a plane which passes through or suiiiciently nearto the bearing for the head produces substantiallv no twisting effect on the bearing.

Other objects and advantages of the invention will be made evident hereinafter. y

Referring to the two sheets of drawings in which I illustrate a preferred form of the invention:

Fig. l is a diagrammatic view showing the utility of the invention for orchard irrigation.

Fig. 2 is a plan view of Fig. 1.

Fig. 3 is a plan View of a sprinkler of my invention.

Fig. 4 is a section taken on the line 4-4 of Fig. 3. l

Fig. 5 is a section taken on the line 5--5 of Fig. 4.

Fig. 6 is a. perspective view of an oscillator which forms a part of the invention.

Fig. 7 is a perspective View of a secondary nozzle of the invention.

Fig. 8 is a diagrammatic view illustrating a principle of operation of the invention.

Referring'partioularly to Fig. 1, I show a header pipe 11 which extends below the surface of the ground indicated at 12. Extended upward from the header pipe 11 is a vertical stand pipe 13 having a valve 14. A revolving sprinkler 15 having the features of my invention is'attached to the upper end of the stand pipe 13. The sprinkler 15 is placed high enough to delivery water over trees 17 of the orchard. Fig. 1 illustrates one use of the invention but it should be understood that the invention may be used wherever the ordinary revolving sprinkler is used.

The details of the invention are illustrated in Figs. 3 to 8 inclusive. The sprinkler 15 has a bearing 20 in the form of a tube which is secured to the upper end of the stand pipe 13 (or any Vother water supply pipe) by means of a coupling 21. Rotatably sup ported by the bearing 20 is a head 22 of. the sprinkler. The head 22 includes a tube 23 having a socket 24 into which the bearing 2O is extended. A retaining nut 25 is screwed onto the lower end of the tube 23 for preventing the head 22 from being removed from the bearing 20, this nut extending around an annular shoulder 26 of the bearing 20.

. The upper end of the tube 23 is threadedly secured in an opening 27 of a body 28. A

I passage 3() of the tube 23 is in communication Y with a cavity 31 of the body 28. Extended from the body 28 is a gooseneck 33 having a. passage 34 formed therethrough which is in communication with the cavity 31. The gooseneck 33 includes an inner portion which curves upward and then downward, and an outer portion which extends upward. Threadedly secured in the outer end of the goos'eneck 33 is a primary nozzle 35 which is in communication with the passage 34. As illustrated in Fig. 3 the inner part of the gooseneck extends radially from the center of rotation X-X of the head 22. The outer portion of the gooseneck 33 and the primary nozzle 35 extend non radiallywith repsect to the a-Xis X-X as indicated by the line Y-Y. The outer part of the gooseneck and the nozzle are on a bias of from three degrees to five degrees.

VThe'bod'y 28 provides a cylindricalchamber 37 which is arranged adjacent to the cavity 31. rlhe chamber 37 is connected to the cavity 31 by means of a tangential opening The cavity 31 is provided with a floating strainer formed of a perforated tube 42 so that large particles of sand or gravel cannot pass through the opening 38 into the cylindrical chamber 37. The upper part of the cylindrical chamber 37 is closed by a cover 39 which is secured to the body 28 by suitable screws 40, there being a packing 41 to prevent leakage. Arranged in the cylindrical chamber 37 is an oscillator 43. The oscillator 43 is in the form of an eccentric weight pivoted on a quill 44. Vhile this weight is an eccentrically pivoted weightin that its pivot is disposed eccentrically relative to its mass and the weight is thus unbalanced, said pivot is vpreferably located at the center of said chamber. The lower end of the quill 44 .-1 journals in a bearing 46 provided by the body below the cylindrical chamber 37. The upper end of the quill 44 journals in a bearing 47 provided by a central boss 48 of the cover 39. The quill 44 is restrained from axial movement by meansof a nut 50. Lubrication is supplied to the lower bearing 46 through the opening of the quill 44. The oscillator 43 is provided with an arcuated face which is formed on a radius which is slightly less than the radius on which a cylindrical face 54 of the cylindrical chamber 37 is formed. There is, therefore, an arcuate spac 56 between the faces 53 and 54. Carried by the oscillator' 43 is a vane 57. The vane 57 is arranged in a vertical plane and is pivoted to the oscillator 43 bymeans of a vertically extending pin 58. The outer part of the vane 57 extends outward beyond the arcuated face 53 and terminates adjacent to the cylindrical face 54. The purpose of the vane 57 is to close the forward part of the arcuated space 56.- The vane 57 may, however, be swung into the position indicated by dotted lines 60 in Fig. 5 when an obstruc- I tion is encountered so that the oscillator will not be prevented from rotating. The water which enters the cylindrical chamber 37 through the tangential opening 38 swirls in the cylindrical chamber and therefore causes the oscillator 43 to rotate.

Connected to the lower part of the cylindrical chamber 37 is a passage 63 which is formed in the lower part of the body 28. Secured in the outer end of the passage 63 is a secondary nozzle 64. rfhe secondary nozzle 64 is shown in detail in Fig. 7. This nozzle compri ses a passage 65 which has a mouth 66 formed at the outer end thereof. Cut in the outer end of the nozzle 64 and connected to the mouth 66 is a slit or kerf 67. The purpose of the slit is to cause the stream issuing from the secondary nozzle 64 to be wide and to be formed to one side of a center line projec-ted from the axis X-X of the sprinkler through thecenter of the passagel 65 and mouth 66. It desired a small split 68 may be provided on the opposite side of the mouth 66 to additionally widen the stream.

The operation or" the sprinkler is as follows:

The valve'14 in the stand pipe 13 is opened in order to supply water to the sprinkler 15. rllhis water passes upward through the opening in the bearing 2O and through the passage 30 into the cavity 31. Part of the water flows from the cavity 31 through the passage 34 in the gooseneck 33 and issues from the primary vnozzle 35 in the form of a stream 75 as illustrated in Figs 1 and 2. The sprinkler is adapted to irrigate an area indicated by the dotted line 76. The stream is adapted to irrigate an annular area between the dotted line 76 and the dotted line 77. The nozzle 35 is designed so that the stream 75 will be long and narrow. The stream 75 is non-radial with respect to the axis of rotation X-X of the head 22 by reason of the fact that the nozzle 35 is non-radial; therefore, the reaction of the stream on the head 22 causes the head to rotate. The rotating tendency will be quite small, however, because oi the fact that tlie nozzle is only from three degrees to live degrees bias. The rate of rotation of the head 22 is one-half R. P. M. and up. It will be seen that the head rotates so slowly that there will be no whipping of the stream 75. The water issuing Jfrom the nozzle 35 will be in asubstantially quiet state because the turbulence has been removed therefrom in passing through the gooseneck In the ordinary sprinkler the arm contains only one bend which gives the water a turbiilent action. As previously pointed out, part of the kinetic energy is dissipated; consequently the water is not thrown as far as possible. In my invention the gooseneck 33 eliminates turbulence because the second bend ,in the gooseneck 33 acts upon the water oppositely from the first bend and therefore the turbulence formed in the water when passing through the first bend is neutralized. rl`his makes it possible to increase the length of the stream 75 and consequently increases the area which the sprinkler 15 is capable of irrigating.

A portion of the water passes through the floating strainer 42 and through the tangential opening 38 into the cylindrical chamber 37. The water entering the chamber 37 tends to follow the cylindrical wall 54 and consequently causes the oscillator 43 to rotate. The vane 57 normally rests in the position shown in full lines in the drawings and thus closes the forward end of the space 56 so that the force of the water will be applied to the oscillator. It any particles of sand should move into the space 56 it will not prevent the oscillator 43 from rotating, since the vane 57 may, when it engages this obstruction, move into dotted line position'GO in Fig. '5 and thus pass by it. It will be seen that if the arcuate face 53 were very close to the cylindrical face 54, the particles of sand might causethe oscillator to bind.

The oscillator 43 prevents the head 22 from sticking. The head. by the action of the oscillator, is given an oscillating movement, as illustrated best in the diagram,

Fig. 8. Referring to Fig. 8, the line 78 is same direction as the reaction of the streamv 75 tends to move it. During this time the head 22 moves an angular distance indicated at A and the line 78 moves Jfrom the position indicated bythe numeral 1 into the position indicated by the numeral 2. When the oscillator moves from the position indicated by dotted lines 81 into the position 80, the torce is applied to the head 22 in opposition to the force applied by the stream 75 and in a direction which tends to rotate the head 22 in an opposite direction from that indicated by the arrow 79. At this` time the head 22 is moved in a direction reverse to that indicated by the arrow 79 an angular distance represented at B. At this time the line 78 moves from the position 2 into the posi-l tion 3. ln view of the fact that the torce of reaction of the stream 75 and the torce created by the oscillator are in opposition, the angular distance B is less than the angular distance A. The result is that the head 22 has advanced in the direction of the arrow 79 an angular distance equal to the angle between the positions 1 and 3 of the line 78. During the neXt half of rotation of the oscillator, that is, a movement from the position 80, the line 78 moves from the position 3 into the position 4, the head 22 ymoving in the direction of the arrow 79 an angular distance represented by C. During the4 next half revolution ot rotation of the oscillator the head 22 moves in a direction opposite to the arrow 79 an angular distance represented by the arrow D, the line 78 moving from the position 4 into the position 5. The next half revolution of rotation of the oscillator results in the head 22 moving an angular distance indicated by E, the line 78 moving from the position 5 into the position 6. It will be seen that the oscillator actually oscillates the head 22 and this oscillation supplies the necessary vibration to prevent the head from sticking. In Fig. 8 the arc of oscillation is greatly exaggerated to illustrate the principle of operation. Vhen the oscillator is Ilu Idil

operating at normal speed, which is about 1000 R. P. M., the oscillation of the head is imperceptible. In experimenting, a head was built in which the oscillator voperated very slowly. In this head it was possible to observe the oscilla-tions of the head.

The water passes from the cylindrical chamber 37 through the passage 63 'and into the secondary nozzle 64. The water issues from the secondary nozzle 64 in the form of a stream S5. The stream 85 is quite wide because of the kerf 67 and the split 68 and therefore does not have the throw that the stream 75 has. The stream 85 irrigates the circular area inside the dotted line 77. The stream 85 is offset from a center line extended 'through the axis of rotation X-X and the center of the secondary nozzle 64. When the nozzle 64 is turned so that the lerf 67 is in the position shown in the drawings, the stream 65 is so ta-ngentially directed that it reacts on the headQQ and tends to cooperate with the stream 75 in rotating the head. The secondary nozzle 64, however. may be rotated into an opposite position so that the stream S will oppose the stream 7 5, and the head 22 will not move at all. By turning the secondary nozzle 64 it will be seen that the rate of rotation of the head 22 may be regulated.

The wind resistance against the streams 75 and 85 is substantially equalized by making the` stream 85 quite wide. If the stream 85 -is as narrow as the stream 75, the wind resistance of the stream 75 would be greater t because it is much longer than the stream 85.

By widening the stream 85 the difference in length of the streams is compensated for and the wind resistance is equalized.

The plane of reaction of the water on the head may be considered for the present purpose as extending at right angles to the drawing in Fig. 4 and along the line ZZ. The line Z-Z intersects the axis of rotation X-X sufficiently close to the bearing to produce but .a minimum of force tending to twist the head. The reactionary force, due to the slight bias of the outer end of the gooseneck along the line Y-Y, is nearly radial and is in a plane which does not disalign the head. The bearing surfaces will therefore be in engagement throughout their length with the result of a minimum of wear. In the preferred form of my invention shown herein, the plane reaction Z-Z intersects the axis i' X-X near the upper end of the bearing and below the head. In this embodiment the plane of reaction Z-Z is positioned by properly shaping the gooseneck 38 to hold the nozzle so that the stream issues in the plane Z-Z.

As previously pointed out, it is an object of this invention `to neutralize turbulence of the water before it is discharged from the primary nozzle, and to this end the primary tubular arm is in the form of a gooseneclr having inner and outer portions which curve in opposite directions.

By means of various tests, I have found that water flowing through a curved conduit attains a certain turbulence, particularly along the short or inside curve, and that water discharged from a sprinkler arm having a single curve tends to break up into drops almost immediately after leaving the discharge nozzle, this being due to such turbulence. Upon the assumption that if a curve in one direction produced such undesirable turbulence, a reverse curve would have a neutralizing effect eliminating the turbulence, the tubular gooseneclr having the reverse curve as herein disclosed, was designed, and upon test it was found that the discharved water was thrown to a relatively great distance before separation into drops and that the maximum flight of the drops was ten per cent greater than of those discharged by the single curve arm under the same pressure conditions.

1While it would be logical to assume that in order for the second curve to neutralize the turbulence set up in the first curve, said second curve would have to extend through the same angular distance as the first curve, that is, the second curve would have to terminate in a plane parallel to that in which the first curve begins, extensive tests have proven that the gooseneck herein disclosed does neutralize the turbulence even though the second curve is of lesser angular extent than the first, and although I may not be able at this time to give a correct explanation of the action taking place within the gooseneclr, it is quite probable that the turbulence is not immediately initiated at the beginning of the first curve, but at a point further along the curve, that is, it may be that the stream will fiow some distance into the first curve before its direction is altered sufiiciently to cause turbulence which would be at all perceptible, thus the first curve would have a turbulence'generating length which would be less than its actual length, and for this reason, a turbulence neutralizing second curve of the same radius as the first curve would have to have an axial length equal only to the turbulence generating length of the first curve. Since this length is less than the actual axial length of the first curve, it is obvious that with curves of equal radius, the

axial length and angular extent of the second curve may be less than that of the first curve, the ratio probably depending somewhat upon the pressure of the water supply, which pressure may have an influence upon the time of initiation of the turbulence.

Thus it was found that with reverse curves of equal radius the extent of the second curve could be such as to discharge at a considerable angle to the vertical and still function to fully neutralize the turbulence. Hotwnozzle 35.

ever, since it was desired to discharge the water in a more nearly horizontal direction, it became necessary to further lessen the angular extent of the second curve and in so doing, it was discovered that it was at the same time necessary to lengthen the axial or arcuate length of this second curve in order to neutralize the turbulence, the solution of the problem appearing to be that, if the second curve is made less abrupt by increasing its radius, its neutralizing effect per unit of axial length is lessened and its axial length must therefore be increased, so that the neutralizing effect may extend over a greater period of time. In other words, the explanation seems to be that if a short, abrupt, second curve will neutralize the turbulence created by a short, abrupt, first curve, a longer, less abrupt second curve will serve the same purpose, the assumption being that while the less abrupt .second curve acts slower, it has a longer time in which to effect complete neutralization. In any event, there appears to be a certain relationship between the relative radii of the two curves of the gooseneck and therelative axial length of these two curves which permits the second curved to be formed to deliver the water at any desired angle, it being understood that as the direction of delivery approaches the horizontal, the radius andthe axial or arcu-A atelength of the second curve will be proportionately increased.

It will therefore be understood that the two curves of the gooseneck may be the same or dissimilar, depending upon the angle of delivery desired, it being of particular importance that the two curves be in substantially the same plane so that the second curve is aL reverse curve relative to the first curve, thevbias of the second curve (as designated by the line Y-Y in Fig. 3) being of such small degree as to have no appreciable effect upon the Jfunction of the second curve.

Thus the term gooseneck as herein used is intended to define a tubular arm which is curved in one direction and is then curved in an opposite direction so that the fiow inthe rst curve is reversed in the second curve in a manner to neutralize turbulence of the stream before discharge.

' From the foregoing description it will be seen that the sprinkler of my invention will irrigate a larger area than the ordinary sprinkler of the saine size because the head rotates very slowly and because the turbulence is removed from the water, forming the long stream 7 5 before it issues from the primary These two features eliminate a whipping of the stream 7 5 and prevent dissipation of kinetic energy.

The head may rotate very slowly because of the oscillator 43 which operates, as previously explained, to prevent a binding or freezing of the head.

' The rate of rotation may be adjusted by turning the secondary nozzle 64. The head will uniformly rotate and not be aected by the wind because the wind resistance of the two streams is substantially equal. The features of the invention just enumerated provide a sprinkler which is superior to any on the market today.

I claim as my invention:

l. An irrigation sprinkler comprising: a support; a head cai'ried by said support; a gooseneck conduit extended from said head and having imperforate walls; and a nozzle carried by said gooseneck at its outer end, said gooseneck having a curved inlet portion and a reversely curved portion in substantially the saine plane and relatively proportioned to neutralize turbulence of flow initiated in the curved inlet portion. l i

2. An irrigation sprinkler comprising: a support; a head rotatably carried by said support; a gooseneck conduit extended from said head and having imperforate walls; and a nozzle carried by said gooseneck at its outer end, said gooseneck having a'curved inlet portion and a'reversely curved portion in substantially the same plane and relativelyr proportioned to neutralize turbulence of How initiated in the curved inlet portion.

3. An irrigation sprinkler comprising: a support a head rotatably'carried by said support, said head having a liquid passage; a primary nozzle carried bysaid head in communication with said passage, said primary nozzle being arranged so that the reaction of liquid fiowingtherefrom will tend to rotate said head but is normally incapable of doing so; and an oscillator carried by said head and operated by liquid from said passage for preventing said head from sticking, said oscillator being in the form of an eccenfl trically pivoted rotary weight arranged to rotate about a vertical axis so as to oscillate the Ahead in the plane of its rotation. i

4. Anirrigation sprinkler comprising: a

support; a head rotatably V'carried by saidv support, said head having a liquid passage;

a primary nozzle carried by said head in comber, the liquid passing through said chamber issuing from saidvsecondary nozzle.

`5.' An irrigation sprinkler comprising: a support; a head rotatably carried by said ids iio

iso

support, said head having a liquid passage;

a primary nozzle carried by said head in communication With said passage, said primary nozzle being arranged so that the re- '55) action of liquid iiowing therefrom Will tend to rotate said head but is normally incapable of doing so; a chamber; an oscillator eccentrically pivoted in the chamber of said head, said oscillator being arranged for operation 1.9; by liquid from said chamber to prevent said head from sticking and being rotatable about a vvertical axis so as to oscillate the head in the plane of its rotation, said chamber being joined to said passage and a secondary nozzle l@ carried by said head in communication With said chamber, the liquid passing through said chamber issuing from said secondary nozzle. 6. Anirrigation sprinkler comprising: a support; a head rotatably carried by said 20, support, said head having a liquid passage; a

primary nozzle carried by said head in communication With said passage, said primary nozzle being arranged so that the reaction of liquid flowing therefrom Will tend to ro- ;tate said head; an oscillator pivoted in a cylindrical chamber. of said head for oscillating the head in the plane of its rotation, said chamber being connected to said passage so that liquid may pass through said `chamber and rotate said oscillator, said oscillator not engaging a cylindrical Wall of said chamber; and a vane pivoted to said oscillator for substantially closing a space between said oscillator and said cylindrical 1' Wall.

7. An irrigation sprinkler comprising: a support; a head rotatably carried by said support, said head having a liquid passage; a primary nozzle carried by said head in comjmunicatio-n with said passage, said primary nozzle being arranged so that the reaction of liquidflovving therefrom Will tend to rotate said head but is normally incapable of doing so; a chamber; an oscillator carried in the j chamber of said head, said oscillator being arranged for operation by liquid from said chamber to prevent said head from sticking and being rotatable about a vertical axis so as to oscillate the head in the plane of its Y`rotation, said chamber being joined to said passage; and a secondary nozzle carried by said head in communication vvith said chamber, the liquid pssing through said chamber issuing from said secondary nozzle, said secondary nozzle being so formed that a stream flowing therefrom may be pointed in different directions.

8. In an irrigation sprinkler of the class described, the combination of: a stationary bearing member; a rotatable head above said bearing member; a rotatable bearing member depending from said head and cooperating With said stationary bearing member to rotatably support said head a gooseneck con- 65 duit extending from said head, said gooseneck having a curved inlet portion and a rev-erselyV curved portion in substantially the same plane and relatively proportioned to` bearing member to produce a minimum twisting action.

- 9. In an irrigationv sprinkler oi the class described, the combination of: a stationary bearing member; a rotatable head above said bearing member; a rotatable bearing member depending from said head and cooperating with said stationary bearing member to rotatably support said head; a gooseneck conduit extending from said head, said gooseneck having a curved inlet portion and a reversely curved portion in substantially the same plane and relatively proportioned to neutralize turbulence of flow initiated in the curved inlet portion; and a nozzle secured to the outer end of said gooseneck through which Water issues, said nozzle being so positioned that the plane of reaction of the issuing Water intersects the axis of rotation of said head near the upper end yof said stationary bearing member.

. l0. In an irrigation sprinkler, the combina.- tion of: a support; a head rotatably carried by said support and having a liquid passage; a discharge nozzle carried by said head'in communication with said passage and arranged so that the reaction of liquid flowing therefrom will tend to rotate said head but is normally incapable of doing so; and an oscillator carried by said head and operated by liquid from said passage for` preventing said head from sticking, 'said oscillator being in the form of an unbalanced rotary VWeight arranged to rotate labout a vertical axis so as to oscillate the head in the plane of its rotation.

l1. In an irrigation sprinkler, the combination of: a support; a head rotatably carried by said support and having a liquid passage; a discharge nozzle carried by said head in communication With said passage and arranged so that the reaction of liquid flowing therefrom will tend-.to rotate said head but is normally incapable of doing so; and an oscillator carried by said head and operated by liquid from said passage for preventing said head from sticking and being rotatable about a vertical axis so as to oscillate the head in the plane of its rotation, said oscillator being'in the form of a rotary fluid-propelled unit eccentrically journalled in relation to its mass.

12. In a sprinkler the combination of: a support; a head rotatable on said support and having a Water passage therethrough;

means for producing a force tending to rotate said head but is normally incapable of doing so; and oscillation means in said passage arranged to be operated by the Water flowing therethrough rotatable about a vertical axis for oscillating said head in the plane of its rotation.

13. In a sprinkler the combination of: a support; a head rotatable on said support and having a Water passage therethrough; means 'for producing a force tending to rotate said head but is normally incapable of doing so; and oscillation means pivoted for oscillation in said Water passage in substantially the same plane as the plane of rotation of said head, said oscillatingmeansbeing rotatable about a Vertical axis and said oscillation means being operable by the Water flowing through said Water passage.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 3rd day of December, 1926.

WALTER VAN E. THOMPSON. 

